Process for the dehydrogenation of



Patented Oct. 17, 1944 PROCESS FOR THE DEHYDBOGENATION OF GASEOUS ANDLIQUID PETROLEUM HY- DROCARBONS Herman B. Kipper, Accord, Mass.

No Drawing. Application November 4, 1942, Serial No. 464,552

2 Claims. (Cl. 106-221) Applicant has had a number of patents grantedhim on oxydehydrogenation processes pertaining to petroleumhydrocarbons. Also in patent application, Serial No. 561,158 ofSeptember4, 1931, the following description of processing for theproduction of unsaturated hydrocarbons from more saturated ones occurs:

I have found that it is possible partially to oxidize the hydrocarbonsby the use of oxygen, in other words to oxidize the hydrogen to formwater without oxidation of the carbon content of the molecule. I

In order to carry out the experimental runs, a high pressure resistantcylinder was filled with nitrogen gas at about fifty to seventy poundspressure per square inch. A pump circulated this gas, to which oxygenwas added in the desired percentage, at the rate of about one liter perI minute (at fifty to seventy pounds pressure) through a heated reactionchamber through which the hydrocarbons were also circulated.

Two series of experimental runs were made. In the first runs thehydrocarbons-were circulated through the reaction chamber at the rate offive grams per minute, whereas oxygen was mixed with the circulatingnitrogen in such percentage that approximately .3 of a gram per minuteof said oxygen was circulated. The pressure in the reaction chamberwasflfty pounds and the temperature thereof 375 degrees C. In twentyminutes 100 grams of hydrocarbons and 6 grams of oxygen had beencirculated. The resulting products, including, among others, oxidizedhydrocarbon and H20, showed a 2% carbon dioxide (CO2) yield.

In the second series of runs the percentage of oxygen was increased sothat 1 gram per minute thereof was circulated with the 5 grams ofhydrocarbon and with the nitrogen at the same pressure and temperaturein the reaction chamber. In twenty minutes grams of oxygen wascirculated. The resulting productsshowed a 7% carbon dioxide yield.

In each case the contents of the gas reaction chamber, pumps, reservoir,etc., approximated 22.4 liters, or practically the volume occupied byone-gram-molecular-weight of gas at normal pressure. Since the finalpressure in each case was about 60 pounds, approximately 4 moles of gaswere in the reaction chamber pumps etc., at the end of each run.

One molecule CO2 weighs 44 grams.

2% X44 gramsx 4 moles: 3.5 gms C02 7%)(44 grams 4 moles=12.3 gms CO2Respectively. therefore, in the two runs 3.5 gms of CO2 and 12.3 gms ofCO2 were formed.

Since, in all, in the first run 6 grams of oxygen was used and in thesecond run 20 grams of oxygen was used, the percentage of oxygen X-=0.42 or 42% and 32 12.5 EXW=0A5 01 45% 7 Thus, about 42-45% of theoxygen used combined with carbon at the above'temperature of operation,whereas, excluding a very small percentage, a matter of a few tenthspercentage of oxygen found in the residual gas, the greater percentage,or let us say about 58%, combined with the hydrogen. If each atom ofcarbon in the hydrocarbon molecule had combined with it originally twoatoms of hydrogen, which in turn would combine with half a molecule ofoxygen, the total oxygen used for oxidizing the carbon atom and hydrogenatom combined with it should be raised 50% or to a total of 21%. Thus,with a CH2 group of the hydrocarbons in the CH: group to 37% 42-21 inthe CH2 group, of the oxygen utilized acted selectively to oxidize thehydrogen. At 200 to 300 degrees C., practically all of the oxygen usedacted selectively, no carbon dioxide, or at most only a few tenthspercent (this small percentage might well be within the limits of errorof my analytical method) were found in the residual gas.

The catalytic materials used were a mixture of finely divided copper andiron oxides with asbestos as the carrier, the preferred catalyticcombination being made up of the above oxides secured by aqueousalkaline precipitation of their hydrates from their soluble sulphates inequimolecular proportions, with suitable washing and drying of thehydrates to produce the pure oxides.

In his application Serial No. 383,930 of March 17, 1941, the followingparagraphs relative to dehydrogenation with the use of metal oxidecatalysts occur in the description:

In the above connection applicant fused together about eighty percent ofantimony and twenty percent of antimony trioxide. The fused mass wassubsequently crushed. The coarser particles, not passing through a50-mesh screen, were used as a catalytic material for selectiveoxidation or dehydrogenation with the use of oxygen and the fines forsimilar work when employing nitri acid. Such fusions were made withcopper and ferric oxide and with the addition of tin. Tin, of course,aids greatly in reducing the melting-or fusion point of the mass, but ofcourse such point must not be carried below that to which the catalystis to be subjected. Also, tin in some cases appeared to prevent adequatefusion between the metal and its oxides.

In dehydrogenation work using air at about two hundred and fifty degreesand fifty pounds pressure and the metallic oxides fused catalysts Justdescribed, practically ninety-nine percent of the gas acted as adehydrogenation agent or in other reactions with the petroleumhydrocarbons, only one to two-tenths percent carbondioxide being foundin the residual gas. The reaction tube used in this work was about sixfeet long and one and one-half inch inside diameter and was filled forthe first two-thirds with a fusion mixture of five parts antimony byweight to one part antimony trioxide, and the last third with a fusionmixture of three parts antimony to one part of its oxide. The firstfusion mixture rapidly reduces the oxygen content, initially that of airor twenty percent, to about ten percent, and the second fusion mixtureutilizes the residual ten percent, without burning or formation ofcarbondioxide, so that very high speeds of reaction can be brought abouteven at relatively low operating temperatures. About five to six litersper minute of air were forced through the tube and c. 0. per minute ofpetroleum oil. Copper or ferric oxide fusion mixtures were similarlyemployed."

Also part of a sentence, relative to dehydrogenation with the use ofmetal oxide catalysts, taken from the above application reads asfollows: the employment of new catalytic condensation agents, andfinally the use of catalysts made up from the fusion of the metallicoxides described in Patent No. 2,224,603, with the pure metalsthemselves.

Finally in this patent application descriptions occur covering theemployment ascatalysts for oxy-dehydrogenation work of the oxides ofmetals and of the metallic elements themselves, which form lower andhigher oxides, as antimony, copper, iron, silver, tin, bismuth, cobalt,chromium, manganese, cadmium, lead, molybdenum, mercury, nickel,tungsten and vanadium. The above two applications were permitted toexpire. In his application Serial Number 373,322 of January 6, 1941, thefollowing descriptive matter occurs:

In his applications Serial Numbers 333,389 of May 3, 1940, now issuedinto Patent Number 2,274,204 of February 24, 1942, and 370,005 ofDecember 5, 1940, applicant describes processing for the selectiveoxidation of hydrocarbons, both liquid and gases. Copper and iron, theiroxides and hydroxides, were used as catalysts for dehydrogenationprocesses.

Applicant has found new that the combination of metal and oxide ofnickel, cobalt, manganese, antimony and tin may be used in place ofcopper and iron and it is practically certain that other metals may besimilarly substituted.

In place of copper iron oxides, nickel, cobalt, tin, antimony andchromic oxides have been satisfactorily substituted as also molybdic,tungstic and vanadic acids or their anhydrides, actually, of course,oxides. Mercury and arsenic have been eliminated from our study becauseof their idiosyncrasies respectively to liquify and to poison.

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Hydroxides, as ferric hydroxide, copper hydroxide, chromic hydroxide,etc. may be satisfactorily substituted for oxides. It goes withoutsaying that salts that would decompose under the operating conditions tooxides might be substituted for the respective oxides.

From the operational data it will be seen that the elements underconsideration cannot be classified under a single group or even severalgroups of the atomic table. Applicant has chosen at least one elementfrom a group for experimentation thus far completed. There is oneproperty that is common to all the metals or elements that have beenfound operationally serviceable to the processing. The metals underconsideration constitute the group of so-called common elements known toform lower and higher oxides. They also constitute the same group ofmetals or elements that applicant found serviceable in selectiveoxidation of petroleum hydrocarbons to unsaturated hydrocarbons when heemployed nitric acid for such oxidation purposes. Description of thisprocessing is contained in his Patent No. 2,224,603 of December 10,1940. In his nitric acid oxidation processes applicant now also is usinga combination of metallic oxides and metals. 1

Applicant has employed not only metals and oxides in the powdered orfinely divided state, suitably supported, as on asbestos, but also theso-called granular and wire forms of both metals and oxides.

An example of his operation when using powdered or finely dividedconstituents in his catalytic combination is the following: one hundredand fifty grams of powdered copper, fifty grams of copper oxide andthirty-five grams of ferric hydroxide were mixed and spread on twohundred grams of asbestos fiber and cemented thereto by an aqueouscolloidal aluminum hydrate.

' Employing the above catalytic combination at about three hundreddegrees centigrade, practically no carbon dioxide was found in theresidual gas when operating with seven percent oxygen and ninety-threepercent of nitrogen. When operating at the above temperature and withtwenty percent oxygen and eighty percent of nitrogen, about 0.5 percentcarbon dioxide and 0.5 percent oxygen were found in the residual gas.Thus, even when using air, about ninetyseven percent selective oxidationwas established. Operations, although not as good as the above, at muchlower temperatures, as low as one hundred twenty-five degreescentigradeand as high as four hundred degrees centigrade showedselective oxidation.

Generally speaking, selective oxidations or dehydrogenations when usingthe optimum temperature or operation and finely divided catalysts andair, or about twenty percent of oxygen and eighty percent of nitrogen,of from ninety to ninety-nine percent efficiency were secured. Even whenoperating with rather coarse granular copper and ferric oxide, orso-called scales, at about two hundred fifty degrees centigrade in theexit gases there was found about nine percent of oxygen and one percentof carbon dioxide so that better than fifty percent of the oxygen of theair employed had reacted with hydrogen and only five percent withcarbon. At about three hundred degrees centigrade, using the samecatalytic combination, about four percent of oxygen and two percent ofcarbon dioxide were found in the exit gases. Thus at the lattertemperature about seventy percent of the oxygen had reacted with thehydrogen and ten percent with carbon and twenty percent remainedunutilized.

- "This dehydrogenation work was carried out in a chrome nickel irontube, about six feet long, 1 internal diameter, heated by electricresistance furnaces. In the above noted case, the tube was filled withfive kilograms of granular copper and two hundred fifty grams of ironoxide scales. Copper oxide was not used, as under the operatingconditions it is gradually reduced to copper. A superatmosphericpressure of from fifteen to sixty pounds was employed. A petroleum fueloil of about 0.87 specific gravity was used. This was passed through thereaction tube at the rate of about one liter per hour and air was forcedthrough the tube at about four liters per minute. Operating similarly asdescribed, but with the catalyst made up of three kilograms of granularcopper, one kilogram of rather coarse iron turnings and two hundredfifty grams of iron oxide scales at about two hundred fifty degreescentigrade, no carbondioxide was found in theresidual gasbut the lattershowed a twelve percent oxygen content. At three hundred degrees, aboutthree-tenths percent carbon dioxide and two percent oxygen were found.Thus iron requires a higher operating temperature but the formation ofcarbon dioxide is kept at a very low figure.

"It was found, unfortunately, that the so-called iron oxide scalesgradually disintegrate at the operating temperatures described, so thatthe latter would not be serviceable for commercial QM operat on. Inemploying finely divided particles of the catalysts and a carrier, asasbestos fiber, the former have to be cemented to the carrier, as withcalcium silicates, aluminum hydroxide, etc. The method is not whollysatisfactory. To get perfect oementation without vitiation of thecatalysts has been found difficult. Therefore, appli cant employed thegranular form of catalysts noted and was very gratified and surprised tofind that even with these larger aggregates of the catalytic materialsrelatively excellent results were secured. As noted, however, granularcopy per oxide and iron oxide scales disintegrate. He

' therefore tried fusion of ferric oxide with molylbdic trioxide, theanhydride of molybdic acid, using from fifty to seventy-five percent ofthe ferric oxide to fifty to twenty-five percent of the molybdicanhydride. Similar fusions were made between ferric oxide and antimonyoxide and ferric oxide and silver vanadate. These fused materials aremore or less granular or easy to disintegrate and after breaking up thefines are discarded and the material obtained on a twentymesh screenused for the catalyst.

"In using chromium, molybdenum, tungsten and vanadium oxides inconjunction with ferric and other metal oxides, chromates, tungstates,etc. possibly are formed. However, these act similarly to the oxides, oras if they were in separate physical and not chemical combinations, sothat such possible chemical combinations should remain inherent to theprocessing of applicant. The same general statement would, of course,

- apply to manganates and plumbates. On the other hand the barium saltsof tungstic and molybdic acids were tried and found practicallyvalueless in applicants dehygrogenation work. It is thus only thecombination of metallic oxides and metals already outlined that act withhigh efficiency in the dehydrogenation processing described.

'The rate of fiow of oil through the reaction tube may, of course, bealtered at will and in accordance with the percentage of unsaturation ordehydrogenation desired. The rate of fiow of air through the tube wasvaried at from'one to Usually, about four litersfive liters per minute.were used. Albove five liters the tube when using the asbestos carrierwas liable to plug and local heating influenced the results. No verymarked differences in results were found when using such variation inthe flow of gases. The better catalytic combinations are hence highlyefiicient. In commercial bubbling towers for the granular forms ofcatalysts and suitably rotating housings for the carrier cementedcatalysts exceptional dehydrogenation efiiciencies should be secured.Applicant has operated at atmospheric to two hundred fifty poundssuperatmosphcric pressure, but the relatively low superatmosphericpressures used, when all points are considered, are probably the mostcommercially suitable.

Using seventy grams of nickel powder, thirty grams of chromic oxide, thegreen oxide, spread on one hundred fifty grams of asbestos fiber ascarrier, at two hundred fifty degrees and thirty pounds pressure, theresidual gases showed no carbon-dioxide content and nine percent ofoxygen; at three hundred degrees four-tenths percent of carbon dioxidewas found present in these gases and no oxygen.

"Employing one hundred grams of powdered antimony and fifty grams offinely divided antimonic oxide spread on two hundred grams of asbestosfiber as carrier at two hundred fifty degrees and about fifty poundspressure, no carbOn dioxide and nine and two-tenths percent oxygen werefound; and at three hundred degrees also no carbon dioxide and one andtwo-tenths percent of oxygen.

"With the use of seventy grams of powdered tin and thirty grams of theanhydride of tungstic acid spread on one hundred eighty grams ofasbestos fiber, no carbon dioxidewas found and nine percent of oxygen;at three hundred degrees tnere was found six-tenths percent of carbondioxide and eight-tenths percent of oxygen was left in the residual gas.

It will thus be noted that antimony proved an excellent catalyst.Silver, gold and platinum come fully within the category of metallicelements found efficient by applicant, but because of high cost he hasconducted no experimentation with the latter two elements, although heused a silver as a catalyst in considerable experimentation in hisnitric acid selective oxidations. The cheaper metals give nearly onehundred percent effective dehydrogenations'as by the processingdescribed. The rarer elements, such as osmium, titanium, thalium, etc.should probably also serve efliciently for the dehydrogenation workdescribed, but it would appear rather absurd to induce higher costs intooperational work when the same has been established practically onehundred percent efiiciently by lower cost methods.

Finally, for his oil dehydrogenation work, about two hundred grams offerric oxide were fused with one hundred grams of silver vanadate, onehundred grams of molybdenum trioxide and one hundred grams of antimonyoxide. The mass was broken upand the fines passing through a twenty-meshsieve discarded. The remainder of about three hundred seventy grams wasmixed with two and one-half kilograms of granular copper and two andone-half kilograms of granular nickel and the reaction tube filled withthis catalytic combination. At two hundred fifty degrees centigrade andfifty pounds pressure, threetenths percent carbondioxide was found inthe residual gases and eight and eight-tenths percent of oxygen. Atthree hundred degrees-about one ferric oxide fused with antimony oxideshould act similarly to the above catalytic combination or possibly evenmore efficiently, g I

A catalytic combination made by precipitating onto an asbestos fibercopper oxide and iron hydroxide from their sulphatesused inequirnolecular proportions by an aqueous sodium hydroxide was employedfor selectively oxidizing a commercial butane-gas. About fifty grams offerric hydroxide and the same weight of copper oxide were deposited onone hundred and fifty grams of the asbestos fiber and, after drying, onehundred grams of powdered copper was further added to make up thecatalytic combination.

Using the above combination and operating at about two hundredtwenty-five degrees centigrade and thirty pounds superatmosphericpressure, neither carbondioxide nor oxygen were found in the residualgas, so that the twenty percent oxygen and eighty percent nitrogenoxidizing mixture had acted one hundred percent selectively. Air wasforced through the reaction tube at about four liters per minute and thebutane gas at about one and one-half liters per minute.

Applicant has found that the catalysts act the same with the hydrocarbongases as with petroleum hydrocarbon oils, only that considerably lowertemperatures must be employed with the gases. Various gravities of oilswere employed from kerosene to fuel oils of 0.92 specific gravity,however, without the necessity of making practically any changes in theoperations. This was true even with the mixture of about, half gasolineand half kerosene.

The unsaturated or dehydrogenated petroleum oils produced have beencondensedwith resins to give drying oils. For these condensations,applicant has used double chlorides, as those of cadmium and sodium andpotassium and copper. He has found these to act similarly to solid acidphosphates and solid hydrogen metallic phosphates. To free these oilsfrom a red discoloration, applicant has found that aldol is veryefficient.

As an example of making an oil of this sort, a dehydrogenated oil, inwhich about three percent unsaturation had been produced, from a 0.87specific gravity petroleum oil, was distilled under vacuum. Distillationtook place between eighty and two hundred ninety-five degreescentigrade. In this oil heated to about eighty to ninety degrees, therewas then dissolved of from five to ten percent of a natural resin, awhite colophony resin being generally employed, and about thirty gramsof finely divided cadmium and potassium chloride were added. The oil washeld at the above temperature for about forty-five minutes underpowerful stirring and filtered off from the catalysts. Both lower andconsiderably higher temperatures were also used for these condensations,but at too high a temperature darkening of the oil becomes excessive.Instead of using distillation the dehydrogenated oils were washed with adilute aqueous solution of sulphuric or phosphoric acid and finally witha small percentage of aldol. The latter has proved an excellent basisfor purification of these dehydrogenated oils. A light lemon-yellowdrying oil was produced having excellent drying oil properties.

Chlorinated petroleum hydrocarbons may be subjected to the processingdescribed by applicant and he has carried out extensive work of thisnature. Also operating with the preferred catalysts described and withfive percent oxygen and ninety-five percent of nitrogen at four hundreddegrees centigrade and thirty pounds superatmospheric pressure, aninety-nine percent selective oxidation was secured, and even at onehundred twenty-five degrees with air and butane considerabledehydrogenation took place. Finally,

. it may be said that the dehydrogenation steps may be carried outfairly successfully even at atmospheric pressure and it is quiteprobable that subatmospheric pressures might be used. Applicant made nostudy of this latter point, as he deemed it was of no commercialadvantage over other processing described. Applicant has not given onepercent of the dehydrogenation analyses carried out, but he believesthat he has given a sufficient number and representative variation ofthese fully to establish his basis of operation and invention. It goeswithout saying that temperatures and pressure and catalytic combinationscould be multiplied ad infinitum without digressing from thefundamentals of the invention described. As an example, for instance, headded five percent of oxygen to air in order to operate with percentagesof oxygen higher than twenty,

but the relative carbondioxide then rises rapidly and he cannot see thatany advantage would be gained by the latter procedure, as air is apretty cheap commodity.

Oxy-dehydrogenation of butane to give butylene is described inapplicant's Patent No. 2,274,204 of February 24, 1942. For this work amixture of iron and copper hydroxides was used. Applicant has tried hismetallic antimony, antimony oxide, 20%, fused or "slagged catalysts forsimilar dehydrogenation of butane and obtained very analogous results.This. oxy-dehydrogenation of butane with a flow of about three litersper minute of the oxidizing gas, consisting of 7% oxygen and 93%nitrogen, at about two hundred and twenty-five degrees and fifteenpounds superatmospheric pressure, and a fiow of gas of about one literper minute of butane practically no carbondioxide and only a few tenthspercent of oxygen was found in the residual gas.

The slagged antimony-antimony oxide catalysts above noted, and elsewheremore fully described in the specifications, after use for a few weeks onoxy-dehydrogenation of petroleum oil unfortunately tends todisintegrate. The tensile strength of antimony is apparently too low forcontinuous operation. A catalyst made up of seventy grams metallicantimony, thirty grams copper and fifteen grams antimonytrioxide, allthree fused together showed considerable better tensile strength andfinally one made up of forty grams antimony, sixty grams copper andtwenty grams antimony oxide had good tensile strength and has beenemployed satisfactorily for the period of a month on oxy-dehydrogenationof a 0.87 specific gravity fuel oil. About once a week this catalyst washeated to about six hundred degrees and air passed over it or forcedthrough the reaction tube to oxidize any carbon or other depositedorganic material. Chromic oxide in conjunction with antimony trioxidehas been similarly slagged with both antimony and copper to give thesemetal, metallic oxide catalysts. The latter had been found excellent onpetroleum hydrocarbons, ranking up with the best of the catalysts notedand on which analyses of products have been given. Applicant will notgive all these analytical data as he believes that he has illustrated bysuch data the possibly more than sufficiently or too fully already, whenconsidering the length of these specifications. Fusion of other metalsas iron, silver, nickel and manganese, more especially with antimony andchromic oxides, was carried out. The catalytic properties of theslagg'ed" catalysts were found excellent in all'cases tried. Seventygrams copper, thirty grams antimony, fifteen grams antimony oxide werefused to produce a catalyst of the type noted. When using three to fourpercent of chromic oxide the porous slag separated on top of the fusedmass was found excellent for the last stages of dehydrogenation or whenthe oxygen had been reduced to a very low percentage.

The unsaturated or dehydrogenated oils were mixed with resin esters oflinseed, tung and soya bean oils to enhance viscosity to give dryingoils of excellent quality. For instance, about eighty-five percent of a0.87 specific gravity dehydrogenated oil was mixed with ten percent oflinseed (2 parts) oil condensed with colophony resin (1 part) and fivepercent of soya bean oil similarly condensed with colophony resin. Alsothe vegetable oils mentioned were condensed with phenol formaldehyde andphenol furfural resins and these condensation products mixed withdehydrogenated oils, likewise for drying oil purposes. The oils thusproduced dry quickly and make good surface coatings with .all the commonpigments tried. Some of the pigments used. were ferric oxide, whitelead, titanium oxide, lithopone, titanox. red lead, chrome yellows andgreens and Prussian blue. From fifty to two hundred and fifty percent ofpigments on weight of oil were employed.

These dehydrogenated oils were also treated with glycerine or ethyleneglycol and the resins noted as also with the resin esters of vegetableoils mentioned. Molecular rearrangements or condensations occur; theviscosity of the drying oil is increased and its weathering qualityenhanced. For instance, the combination noted of eighty-five percentdehydrogenated oil, ten.

percent linseed oil colophony resin ester and five percent soya bean oilresin ester was heated to one hundred and fifty to two hundred degreeswith three to five percent of glycerol for about three quarters of anhour in a closed vessel and the oil thus produced and while hot wasfiltered by suction to free from a small percentage of depositedmaterial. Likewise seven percent of colophony resin, or five percent ofa phenolic formaldehyde resin and three to five percent of glycerine wassimilarly condensed with the unsaturated or dehydrogenated oil byheat'as just noted. Combination of resin and resin ester condensationswas also carried out as likewise condensation with natural and phenolicor furfural formaldehyde resins. Copal and dammar resins were likewisesubstituted for colophony resin and found satisfactory. In all casesexcellent drying oils were obtained. Small percentages of catalysts, assolid phosphoric acid, or, metal hydrogen phosphate, as copper hydrogenphosphate, cadmium and potassium chlorides in combination, or othermetallic chlorides and bromides, as ammonium bromide and cadmiumchloride, were found valuablein aiding these condensations.

Possibly the best drying oil was synthesized by condensing some fourhundred grams of a 0.91 specific gravity petroleum or fuel oil, in whichabout three percent of unsaturation had been established, with fourhundred grams of butylenes, twenty grams of glycerol, fifty grams ofcolophony resin, twenty-five grams of a phenolic formaldehyde resin,twenty-five grams of soya bean oil and fifty grams of tung oil. Theresins were dissolved at about seventy degrees in the unsaturatedhydrocarbon oil and vegetable oil mixture and the catalyst of solidcopper hydrogen phosphate was thoroughly stirred with the oil and resinreaction mass which was then passed into the reaction tube. About fourhundred grams of a commercial butylene gas were I subsequently forcedinto the tube and nitrogen gas, to raise the pressure to about twohundred and fifty pounds. The reaction was carried out during about anhour at about one hundred and fifty to two hundred degrees. Of courseother temperatures might be employed. The oil while still hot wasnevertheless withdrawn from the reaction tube and freed from thecatalyst and any precipitated matter by filtration with the use ofsuction. Applicant found in his earlier work on drying oils thatbutylenes and other ases of the olefinic series if suitably condensedwith other oils and resins gave drying oils with very exceptionalweathering properties.

To enhance the weathering quality of these oils when used for metalsurface coatings to the pigments used. a small percentage, as onepercent, of an acid or hydrogen metal phosphate was added. For instanceone percent of ferric hydrogen phosphate was added to the ferric oxideused in making up a pigmented oil or paint when using the pigment noted.When using a red lead one percent of a lead hydrogen phosphate wasaddedto the pigment. Also diethyl phosphate, about one percent'on weight ofoil, was found valuable for a similar purpose. A separate patentapplication however covers thi: latter finding.

Finally the butylene gas synthesized, as well as commercial butylene,was polymerized to products similar to gasolene that is distilling atabout the same temperature range, by means of borontrifiuoride mixedwith an inert gas, as nitrogen, and at superatmospheric pressure.Although the work was started at about minus fifty degrees centigrade,or at about the temperature of dry ice, it was found that with suitabledilution of the borontrifiuoride by nitrogen and at suitablesuperatmospheric pressure the gasolene'products could be produced atroom temperature or fifteen to twenty degrees. Forinstance 5 to 25% ofborontrifiuoride, by volume, was mixed with to 75% nitrogen and passedthrough the butylene gas condensed to the liquid state by nitrogen atfrom 200 to 2000 pounds pressure. The gaseous mixture ofborontrifiuoride and nitrogen was then bubbled through the condensedgases which were thereby polymerized to liquid products as determinedupon opening of the reaction vessel. As commercial butylene gas containsother unsaturated hydrocarbons, as propylenes and amylenes, andpractically complete polymerization occurred these other unsaturatedhydrocarbon gases must have condensed similarly to the butylenes. Otherfluorides and chlorides, as those of chromium, silver and copper, ,weretried as the catalytic material in place of borontrifluoride but theresults were comparatively poor. 01 course other percentages Ofborontrifiuoride might be employed and other inert gases, as carbondioxide, might be used in place of nitrogen as a diluent gas.

.I claim:

1. In a process for the fabrication of synthetic drying oils the step ofsubjecting petroleum oils to oxygen and an inert gas at superatmospherictemperatures and pressures in the presence 01 a metallic element and theoxide of a metallic element, the metallic element and the metal oxidewith commonly known higher and lower oxides and consisting of copper,iron, nickel, cobalt,

silver, tin, bismuth, antimony, cadmium, chromium, manganese, lead.mercury, molybdenum, tungsten and vanadium and their oxides and finallythe step 01 heating for establishment of reaction the said unsaturateddehydrogenated petroleum hydrocarbons with a. polyhydric organic alcoholcontaining not over three hydroxyl 7 being chosen irom the group 01'metallic elements i6 groups, an oil soluble natural resin and avegetable drying oil condensed with the said resin. i 2. In a processfor the fabrication of synthetic I drying oils the step 01 subjecting apetroleum oil oi about 0.87 specific gravity to air at from onel hundredand twenty-five to four hundred degrees centigrade at superatmosphericpressure in the presence'oi a; metallic element and the oxide of themetallic element, as a catalytic material, the metallic element and themetal oxide being chosen from the-group oi metals and their oxides withcommonly known lower and higher oxides and consisting of copper, iron,nickel, cobalt, silver, tin, bismuth, antimony, cadmium, chromium,manganese, lead, mercury, bolybdenum, tungsten and vanadium and theiroxides, and finally the step of heating for establishment of reactionthe unsaturated, dehydrogenated petroleum hydrocarbons with glycerol,colophony resin, linseed and soya bean oils condensed with colophonyresin, in the presence 01' copper hydrogen phosphate which had beenheated with infusorial earth.

HERMAN B. KIPPER.

